Pages

Wednesday, 22 June 2016

All the Small Things

It’s always
interesting/entertaining/amusing when an animal does something we think is typically
human; a dog riding a bike, a cat playing Candy Crush, a hamster surfing, and thanks
to the internet we can see all these things, what a time to be alive. But the
other week I was surprised to hear of an animal that did something no-one
thought it could do and the repercussions of this could have a major impact on
the world of endometriosis research.

This was a report
I read documenting the first ever observed occurrence of a species of mouse
(the spiny mouse to be precise) having a menstrual cycle. Up until now the only
animals we were familiar with that menstruate were primates like chimps,
gorillas and humans. Other animals have different reproductive cycles
characterised by different hormonal and physical changes in their reproductive
organs. Most other mammals, including mice, undergo an estrous cycle. The estrous cycle, like the menstrual cycle, is
still regulated by hormones such as estrogen and progesterone, but the way
these hormones vary throughout the respective cycles and the effect they have,
differs.

The diagram
below shows how the different hormones that regulate the function of the reproductive
organs changes over the human menstrual cycle and the rat estrous cycle. If you
want to see how these hormones work in humans I've covered it here.

As you can
see, there are quite obvious differences, but also some similarities between
the two. The rat proestrus stage for example, is somewhat similar to the human
day 14 and the rat day 4 resembles the human day 10, but overall they are quite
distinct. In terms of the actual physical changes, menstrual animals shed their
endometrium after each cycle if conception doesn’t occur. This, as some of you
will all too painfully know, is having a period. Estrous animals on the other
hand reabsorb the endometrium if conception doesn’t occur and, although some
animals like dogs might bleed at certain times of their cycle, this is not an
actual period, rather it is caused by estrogen making the blood vessels in the
vagina ‘leaky’.

So the
discovery of a menstrual cycle in the spiny mouse is surprising to say the
least, but why is this relevant to endometriosis research? In order to study
the way in which endometriosis works and develop new treatments we can grow
endometriosis cells in the lab and experiment on them. Unfortunately this tells
us nothing of the complexity of the disease or how endometriosis behaves in a
living organism. For this researchers turn to animal models of the disease. This
is usually achieved by ‘inducing’ endometriosis in a lab animal (typically estrous
mice). However this is far from a perfect model of the disease. Inducing the
disease in mice is achieved by transplanting either pieces of whole uterus, or pieces
of the normal endometrium into the pelvis of the mice. Neither of these gives a
true representation of human endometriosis, but it’s the closest thing
researchers have at their disposal to study endometriosis (there are much more
accurate primate models of endometriosis, but there are numerous reasons, such
as cost, facilities and ethics, that prohibit the use of these animals in most
research centres).

Another problem
is that because normally mice don’t menstruate, the disease will not behave in
mice the same way it behaves in humans due to different levels of hormones in
the body. Mice can be made to have hormonal cycles like humans but this
involves removing the ovaries and supplementing them with hormones and even
this doesn’t represent the complexity of hormonal changes during the human
cycle.

By using an
animal that can menstruate, our models of endometriosis would become more
accurate (in fact we may not need to induce endometriosis in these spiny mice if
they develop it spontaneously, much more investigation is needed to observe
this though). By extension the way we understand the disease in humans and the effectiveness
with which we can develop new treatments will also become more accurate. Additionally,
one of the goals that researchers work towards is reducing the number of animal
experiments that are required to study any given disease. By using an animal that
more closely resembles the human menstrual cycle, it would eliminate the need
for performing additional procedures on lab mice to induce human-like hormonal
cycles.

However,
there is still a lot of work to find out exactly how similar the spiny mouse
menstrual cycle is to the human one. The initial research that has been done
has shown the spiny mouse cycle to be 9 days long. The human cycle is, on
average, 28 days long and, interestingly, the pattern of progesterone levels in
the blood across the spiny mouse cycle almost exactly matches that of the human
cycle.

Although
there is a lot of work still to be done investigating this unusual phenomenon, it
not only has impact for endometriosis research, but also into other female
reproductive conditions, like infertility, pregnancy and menstrual disorders.

I´m 47 years old and have confirmed spread endometriosis (by laprascopi - they call it micro endometriosis, on ovaries and spread in the abdomen), resulting in IVF and so on... I have monthly pain with sickness feeling and also stomach problems, pelvis pain and low energy.

I´ve had too many side effects on birth control pills (even from Mirena) and found no other way than quitting this path. I instead, since getting close to menopause, get HRT with 0,5-1 g estradiol gel/day (divigel), along with cyclic micronised progesteron 2x100mg/day 12-14 days/month (utrogest).

I had increased pain allready 1 month after starting with estradiol (but the pain is normally unpredictable, sometimes better, sometimes worse) - could it be connected to the estradiol? Have taken estradiol for 2 months now. And everyday life is a little brighter :)

What do you think of the risks of the endometriosis to grow with the estradiol?

I also long for menoupaus, do I postpone the menopaus using estradiol?

Many many thank´s for sharing the latest information about endometriosis! Very very much appreciated!

Endometriosis Update

Endometriosis is an enigmatic disease, little is known about its origins, but it affects the lives of millions of women around the world. Despite the apparent lack of advancement in the field of endometriosis research, progress is slowly being made. The problem is that this progress is very rarely reported accurately to the public in a way everyone can understand. This Blog aims to report what is going on in the area of endometriosis research in plain and simple terms, so that everyone can keep up to date. Updates will be pretty sporadic but I'll try to report items of interest as often as possible.